Currently, optical fibers are used in optical backplanes for computers where the distances being traversed is only tens of centimeters. The use of optical fibers allows for higher bandwidth operation because skin effect losses associated with metal conductors is avoided. Thus, it is becoming attractive to develop equipment such as computers and the like in which direct chip-to-chip or board-to-board connections via light is used. In addition to the high speed, low attenuation and higher bandwidth possible per channel with an optical connective device, interference due to electromagnetic energy is eliminated.
Two current optical connective devices which have been developed are identified in publications as the Columbia University design and the Honeywell design. In the Columbia University design a single mode optical fiber is coupled to a buried detector via a carefully machined aluminum guide coupled to a side of a chip. In the Honeywell design, an array of optical fibers are arranged along a single plane and held in alignment via a chemically machined silicon V-groove fixture. The ends of the optical fibers are positioned over detectors in a chip, the ends being beveled to direct light from the optical fibers to the detectors.
The cores of optical fibers are very fine, their core diameter being less than 15 microns. Obviously, therefore, the manufacture of current optical connective devices which requires positioning an end of an optical fiber into a slot or an opening to obtain alignment with a detector or an optical path on a chip or a board not only required great accuracy, but is usually difficult and painstaking.
Clearly, a need exists for an optical connect for chips and boards which is economical to construct, has dimensions which are dependably accurate, and which permits chips and boards to be more closely coupled to each other.
This invention is directed toward an optical connective device which meets these needs.